Torsional vibration damper, clutch disc, and clutch

ABSTRACT

A torsional vibration damper includes a rotational axis, an input part mounted about the rotational axis, an output part rotatable about the rotational axis to a limited extent relative to the input part; a spring device opposing rotation of the output part relative to the input part, a first cam mechanism, and a first intermediate element. The first intermediate element is arranged for radial displacement by the first cam mechanism when the output part rotates relative to the input part. The first intermediate element has a first intermediate element first part, and a first intermediate element second part. In an example embodiment, the damper includes a second cam mechanism and a second intermediate element arranged to be radially displaced by the second cam mechanism when the output part rotates relative to the input part. The spring device is arranged between the first intermediate element and the second intermediate element.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the United States National Phase of PCT Appln. No.PCT/DE2019/100296 filed Mar. 29, 2019, which claims priority to GermanApplication No. DE102018108441.2 filed Apr. 10, 2018, the entiredisclosures of which are incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates to a torsional vibration damper, e.g.,for a clutch disk within a drive train of a motor vehicle, acorresponding clutch disk and a clutch, e.g., for the drive train of amotor vehicle.

BACKGROUND

Torsional vibration dampers are known in automotive engineering, forexample from DE10 2015 211 899 A1, in which an input part and an outputpart that can be rotated to a limited extent relative to the input partare coupled by intermediate elements and spring devices, and the springdevices are not arranged in the circumferential direction. Theintermediate elements are arranged centrally in the axial direction. Theinput part is connected to a friction ring. The formation of thisconnection is complex and restricts the space available for theformation and movement of the intermediate elements such that there arelimits to the possible capacity of the torsional vibration damper. Ithas also been shown that the long-term functionality of the torsionalvibration damper depends on the precision of the manufacture of theintermediate elements. The symmetry or uniformity of the roller tracksin the axial direction may be critical, so that, for example, theindispensable effects of the manufacturing method lead to problems inthe operation of the torsional vibration damper and in terms ofdurability. For example, when the intermediate elements are manufacturedusing a stamping process, the entry and exit of the stamping leads to anon-uniform support surface for the rolling elements in the axialdirection. This can have a detrimental effect on the movement of theindividual components, since the components (input part, output part,intermediate element) can be shifted laterally during operation.

SUMMARY

The present disclosure provides a torsional vibration damper, which isof simple construction and the function of which is independent ofmanufacturing tolerances.

The torsional vibration damper according to the disclosure, e.g., for aclutch disk within a drive train of a motor vehicle, includes an inputpart which is mounted about a rotational axis and an output part Whichcan rotate about the rotational axis to a limited extent relative to theinput part against the action of a spring device. The clutch disk hasleast two torque-transferring intermediate elements which are arrangedbetween the input part and the output part and which are arranged so asto be forcibly displaced in a radial direction by means of cammechanisms in the event of a relative rotation between the input partand the output part. The spring device is arranged between the at leasttwo intermediate elements. Each intermediate element is designed in twoparts.

An example embodiment with two intermediate elements and two springdevices can be constructed simply and efficiently damps vibrations. Thespring device has at least one spring as an energy store, e.g., twosprings, which are connected to the two intermediate elements. Thetorsional vibration damper can be designed, for example, as a splitflywheel with a primary flywheel mass and a secondary flywheel mass witha spring device effectively arranged therebetween, as a torsionalvibration damper arranged in a clutch disk between a lining carrier anda hub, as a lock-up damper in a torque converter or the like. Theproposed torsional vibration damper includes a spring device for dampingrotational or torsional vibrations, which is arranged outside of thetorque path between the input part and the output part. As a result, thespring device can be designed largely independently of the torque to betransmitted via the torsional vibration damper and adapted to its actualtask of vibration isolation.

A two-part construction of the intermediate element is understood tomean that it is made up of two element parts which, for example, areformed one behind the other in the axial direction (in the direction ofthe rotational axis). A design of two symmetrical element parts ispossible. A two-part symmetrical design of each intermediate elementmakes it possible to form the support in the roller tracks in theintermediate element, regardless of the manufacturing method for theintermediate elements, to form a more uniform support surface for therolling elements. At the same time, a multi-part construction of theintermediate elements allows a high degree of flexibility in theconstruction of the torsional vibration damper, which leads to greaterpossibilities in terms of the design of the damper and itscharacteristics.

According to an example embodiment, each intermediate element is formedfrom two element parts designed to be spaced apart from one another inthe direction of the rotational axis. By designing the element parts tobe spaced apart, a fundamentally very flexible design of the torsionalvibration damper can be facilitated, in which a further component suchas the input or output part is received between the element parts in theaxial direction of the rotational axis. This allows a greater scope fordesign with regard to the design and layout of the torsional vibrationdamper. The two element parts may be designed symmetrically to an axisthat is perpendicular to the rotational axis. As a result of thesymmetrical design, a symmetrical distribution of the roller contactsurfaces with respect to the rolling elements can be achieved—even whenusing stamped parts.

According to an example embodiment, the input part is received betweenthe element parts. This enables a simpler and more flexible approach ofa friction element of a clutch disk to the damper, since more space isnow available for the connection of the friction element compared toapproaches known from the prior art without this affecting theinstallation space available for the intermediate element and the springdevice. This provides more flexibility when designing the torsionalvibration damper.

In this connection, the input part may be formed from at least two inputpart elements. In this case, a friction element or a connecting elementto a friction element can be formed between the input part elements andall three components can be connected to one another, for example byriveting. This enables a simple and inexpensive connection of thefriction element and thus the clutch disk.

According to an example embodiment, each intermediate element isreceived between two parts of the output part. This enables a simple andflexible construction of the torsional vibration damper also with regardto the connection to an output shaft of the torsional vibration damper,which may be a transmission input shaft. In this context, eachintermediate element may be formed from two element parts which areformed symmetrically between two parts of the output part.

Furthermore, a clutch disk for a clutch, e.g., in the drive train of amotor vehicle, is proposed which includes a torsional vibration damperas described here, and a clutch which includes a corresponding clutchdisk. Furthermore, a motor vehicle having such a clutch is proposed. Thedetails and advantages disclosed for the torsional vibration damper canbe transferred and applied to the clutch disk, the clutch and the motorvehicle, and vice versa.

As a precaution, it should be noted that the numerals used here(“first”, “second”, etc.) serve primarily (only) to distinguish betweenseveral similar objects, sizes, or processes, and in particular nodependency and/or sequence of these objects, sizes or processesmandatory to each other is purported.

If a dependency and/or sequence is necessary, this is explicitly statedhere or results in a manner obvious to the person skilled in the artwhen studying the specifically described configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

Both the disclosure and the technical environment will be explained inmore detail below with reference to the figures. It should be pointedout that the disclosure is not intended to be limited by the exemplaryembodiments shown. For example, unless explicitly stated otherwise, itis also possible to extract partial aspects of the matter explained inthe figures and to combine same with other components and findings fromthe present description and/or figures. It should also be pointed outthat the figures and, in particular, the proportions shown, are onlyschematic. The same reference numerals designate the same objects, sothat explanations from other figures can be used as a supplement. In thefigures:

FIGS. 1 and 2 show a torsional vibration damper assumed to be known;

FIG. 2 shows a detail of the torsional vibration damper assumed to beknown;

FIG. 3 shows a detail of an example of a torsional vibration damper inthe neutral, undeflected state;

FIGS. 4 and 5 show details of two examples of torsional vibrationdampers in section;

FIG. 6 shows a detail of an example of a torsional vibration damper inthe deflected state;

FIGS. 7 and 8 show two views of the torsional vibration damper in thenon-deflected state;

FIGS. 9 and 10 show two views of the torsional vibration damper in thedeflected state;

FIG. 11 shows an example of a clutch disk; and

FIG. 12 very schematically shows a clutch.

DETAILED DESCRIPTION

In the Detailed Description, the same parts are provided with the samereference symbols. The torsional vibration damper 1 shown as known inFIGS. 1 and 2 includes an input part 2, intermediate elements 3, cammechanisms 4, 5, ramp devices 6, 7, a spring device 8 having energystores 9 arranged between the intermediate elements 3, and an outputpart 10. The input part 2 of the torsional vibration damper 1 of FIG. 1has ramps 11, such as cam tracks of the ramp devices 6, in the two cammechanisms 4 which are opposite one another with respect to therotational axis d of a shaft 17.

Two mutually opposite intermediate elements 3, each having two ramps 12complementary to the input part 2, such as cam tacks of the ramp devices6, and the rolling elements 13 complete the cam mechanism 4 between theinput part 2 and the intermediate elements 3. When the input part 2 isrotated around the rotational axis d, the rolling elements 13 are guidedon the ramps 11, 12 such that the radial movement of the intermediateelements 3 results in a parallel spring compression of the two energystores 9, which are arranged between the intermediate elements 3. Theramps 11 of the input part 2 and the ramps 12 of the intermediateelements 3 together with the associated rolling elements 13 form the cammechanism 4.

The intermediate elements 3 each include a further ramp 14 radially onthe inside, which are operatively connected to ramps 15 arranged in theoutput part 10. When the output part 10 is rotated around the rotationalaxis d in the opposite direction to the rotation of the input part 2,the intermediate elements 3 are also guided via rolling elements 16which roll freely between the appropriately designed ramps 14, 15 suchthat the movement thereof again signifies a parallel spring compressionof the energy stores 9. The ramps 14 of the intermediate elements 3 andthe ramps 15 of the output part 10 together with the associated rollingelements 16 form the cam mechanism 5.

As a result of the coupling of the two cam mechanisms 4, 5 via theintermediate elements 3, the total angle of rotation between the inputpart 2 and the output part 10 results from the sum of the angles ofrotation which are set in the respective cam mechanism 4, 5 having acertain spring compression of the energy stores 9. The torque at theinput part 2 for the rotational movement is supported as a puretorsional moment at the output part 10. The unit consisting ofintermediate elements 3 and energy stores 9 is not subject to anexternal torque effect, but determines the amount of the transmittedtorque via the amount of force from the parallel spring compression ofthe energy stores 9.

The ramps 11, 12, 14, 15 of the cam mechanisms 4, 5 of the torsionalvibration damper 1 are linear in design, for example, to transmit themovements during rotation in the marked direction and to indicate theability to transmit torque in contact via the rolling elements 13, 16 inthis direction. In the case of constructions carried out, on the otherhand, the design of the ramps 11, 12, 14, 15 is a free form as a resultof the desired translations for the torsion characteristic curve whilefulfilling the rolling conditions for the rolling elements 13, 16.

FIG. 3 shows a detail of an example of a non-deflected torsionalvibration damper 1 with an input part 1 which can move in thecircumferential direction 18, an intermediate element 3 which isconnected to another intermediate element 3 (not shown) via a springdevice 8. The movement of the intermediate element 3 in the direction ofmovement 19 is predetermined by the energy store 9 (spring elements) ofthe spring device 8. Furthermore, an output part 10 is formed which isconnected to a shaft (not shown) which has the rotational axis d.

Furthermore, the torsional vibration damper 1 has rolling elements 13which are guided by ramps 11 of the input part 2 and ramps 12 of theintermediate element 3, as discussed above. Furthermore, a rollingelement 17 is formed which is guided by ramps 14 of the intermediateelement 3 and ramps 15 of the output part 10, as discussed above.

FIGS. 4 and 5 show details of two possible examples of torsionalvibration dampers 1 in section, in which the intermediate element 3 isformed in two parts from two element parts 20. These element parts 20are constructed symmetrically and are designed to be spaced apart fromone another in the direction of the rotational axis d, so that the inputpart 2 can be received between the element parts 20.

In FIG. 4, the input part 2 is constructed from two input part elements21 which are connected to one another in a non-positive and form-fittingmanner via rivets 22 enabling a friction element 23 to be fixed betweenthe input part elements 21, e.g., by the rivets 22. The rivets 22 may becountersunk and conical in order to allow a connection of the input partelements 21 that does not cause any further structural restrictions,since the rivet 2 ends flush with the respective axial outer side of theinput part elements 21. The term friction element 23 is also to beunderstood here as an element that serves as a carrier for a frictionring, for example. For example, the friction element 23 may be part of acorresponding friction clutch (not shown here).

FIG. 5 shows an example in which the input part 2 is formed in onepiece. Here, the friction element 23 is fastened to an axial surface ofthe input part 2 by means of corresponding rivets 22.

If FIG. 2 is compared to FIGS. 4 and 5, it can be seen that, in theembodiment according to FIGS. 5 and 6, the bearing surface for therolling elements 13, 17 in the intermediate element 3 or the elementparts 20 is symmetrical and flat, while in the embodiment of FIG. 2, theinfluence of, for example, the non-uniformities of the support surfaceproduced by the punch entry and exit is greater. In this way, a moreuniform movement of the rolling elements 13, 16 in the respective ramptracks 11, 12, 14, 15 can be achieved, in which a lateral movement ofthe components 2, 3, 10 can be reduced.

FIG. 6 shows an example of a torsional vibration damper 1 which isdeflected in comparison to FIG. 3, analogously to FIG. 3.

FIGS. 7 and 8 show parts of a torsional vibration damper 1 in thenon-deflected state, FIGS. 9 and 10 in the deflected state. Reference ismade to the above disclosure. FIGS. 7 to 10 show that a simpleconnection of the friction element 23 to the input part 2 is possiblewithout the shape and the range of movement of the intermediate elements3 being restricted as a result. The intermediate elements 3 or theelement parts 20 can use the maximum installation space and inparticular the maximum possible radius in the clutch disk, so that thesize of the spring devices 8 and in particular the energy store(springs) 9 can be optimized, so that the energy store 9 can provide alarge spring energy.

FIG. 11 shows a clutch disk 24 with a torsional vibration damper 1 asdescribed, for example, in connection with FIG. 4. Reference is made tothe embodiments outlined above. The friction element 23 is connected tothe input part elements 21 by rivets 22. The friction element 23 hasfriction surfaces 25 which can be detachably connected via a frictionalconnection to corresponding friction partners (not shown) forming aclutch.

Furthermore, a hub flange 26 is shown which can be connected via anintermediate toothing 27 to a hub (not shown) which in turn can beconnected to a shaft, for example a transmission input shaft.

Finally, FIG. 12 very schematically shows a clutch 28 with a clutch disk24. The clutch 28 can, for example, be arranged in the drive train of amotor vehicle.

REFERENCE NUMERALS

1 Torsional vibration damper

2 Input part

3 Intermediate element

4 Cam mechanism

5 Cam mechanism

6 Ramp device

7 Ramp device

8 Spring device

9 Energy store

10 Output part

11 Ramp

12 Ramp

13 Rolling element

14 Ramp

15 Ramp

16 Rolling element

17 Shaft

18 Circumferential direction

19 Direction of movement

20 Element part

21 Input part elements

22 Rivet

23 Friction element

24 Clutch disk

25 Friction surface

26 Hub

27 Intermediate gearing

28 Clutch

d Rotational axis

1.-9. (canceled)
 10. A torsional vibration damper for a clutch diskwithin a drive train of a motor vehicle, comprising: a rotational axisextending in an axial direction; an input part mounted about therotational axis; an output part rotatable about the rotational axis to alimited extent relative to the input part; a spring device opposingrotation of the output part relative to the input part; a first cammechanism; and a first intermediate element arranged for radialdisplacement by the first cam mechanism when the output part rotatesrelative to the input part, comprising: a first intermediate elementfirst part; and a first intermediate element second part.
 11. Thetorsional vibration damper of claim 10 further comprising: a second cammechanism; a second intermediate element arranged to be radiallydisplaced by the second cam mechanism when the output part rotatesrelative to the input part, comprising: a second intermediate elementfirst part; and a second intermediate element second part, wherein thespring device is arranged between the first intermediate element and thesecond intermediate element.
 12. The torsional vibration damper of claim10 wherein the first intermediate element first part and the firstintermediate element second part are spaced apart from one another inthe axial direction.
 13. The torsional vibration damper of claim 10wherein a portion of the input part is disposed axially between thefirst intermediate element first part and the first intermediate elementsecond part.
 14. The torsional vibration damper of claim 13, wherein theinput part comprises an input part first element and an input partsecond element.
 15. The torsional vibration damper of claim 14, whereinthe input part further comprises a friction element disposed axiallybetween and fastened to the input part first element and the input partsecond element.
 16. The torsional vibration damper of claim 10, wherein:the output part comprises an output part first element and an outputpart second element; and a portion of the first intermediate element isdisposed axially between the output part first element and the outputpart second element.
 17. The torsional vibration damper of claim 16,wherein the first intermediate element first part is formedsymmetrically relative to the first intermediate element second partbetween the output part first element and the output part secondelement.
 18. A clutch disk comprising the torsional vibration damper ofclaim
 10. 19. A clutch comprising the clutch disk of claim
 18. 20. Atorsional vibration damper comprising: a rotation axis; an input partcomprising a first ramp profile; an output part comprising a second rampprofile; an intermediate part comprising a pair of intermediate partelements, each of the pair of intermediate part elements comprising: athird ramp profile; and a fourth ramp profile; a first roller contactingthe first ramp profile and the third ramp profile; and a second rollercontacting the second ramp profile and the fourth ramp profile, wherein:the first roller and the second roller are arranged to roll along theirrespective ramp profiles when the output part rotates about therotational axis relative to the input part; and the intermediate part isradially displaced by the first roller and the second roller when theoutput part rotates about the rotational axis relative to the inputpart.
 21. The torsional vibration damper of claim 20, further comprisinga third roller, wherein: the input part comprises a fifth ramp profile;each of the pair of intermediate part elements comprises a sixth rampprofile; and the third roller is arranged to roll along the fifth rampprofile and the sixth ramp profile to radially displace the intermediatepart when the output part rotates about the rotational axis relative tothe input part.
 22. The torsional vibration damper of claim 20 whereinthe second roller is longer than the first roller.
 23. The torsionalvibration damper of claim 20 wherein a portion of the input part isdisposed axially between the pair of intermediate part elements.
 24. Thetorsional vibration damper of claim 23 wherein the input part comprisesa pair of input part elements.
 25. The torsional vibration damper ofclaim 20 wherein: the output part comprises a pair of output partelements; and a portion of the intermediate part is disposed axiallybetween the pair of output part elements.
 26. The torsional vibrationdamper of claim 20 further comprising a pair of spring elements opposingradially inward displacement of the intermediate part.
 27. The torsionalvibration damper of claim 20 wherein the input part further comprises afriction disk having a portion disposed axially between the pair ofintermediate part elements.
 28. The torsional vibration damper of claim27 wherein: the input part comprises a pair of input part elements; andthe portion of the friction disk is disposed axially between the pair ofinput part elements.